Super User is a question and answer site for computer enthusiasts and power users. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

At night, when I'm finished using my computer, I put it to sleep. Most of the time, it will stay asleep.

Sometimes, the machine will buzz twice quickly, and then wake back up. No amount of putting the thing to sleep (either by the button or by the menu command) will do it.

I'm running 24" iMac, 2.4GHZ C2D, 4GB DDR2, Radeon 2600HD, and Leopard 10.5.7.

Some tidbits:

  1. Wake on lan is not enabled.
  2. Wake on bluetooth is not enabled, and bluetooth is turned off.
  3. Time machine is not running when I sleep the machine.
  4. The machine will wake even if nothing is plugged in.
  5. There are no applications wanting my attention.
  6. I have not scheduled any events to take place close to midnight that would prevent me from shutting down.

Can anyone suggest why my mac won't stay asleep sometimes? Or a place to start looking?

share|improve this question
up vote 1 down vote accepted

Start the application Console (aka Console Viewer), located at


Look through the system log until you reach the point in time where you Mac woke up and see if it lists the reason for waking up.

share|improve this answer
I will do this, and post the results here. Thanks! – EvilChookie Jul 19 '09 at 6:10

I would start by looking at any devices you have pluged in the machine. Things like usb hubs, scanners, usb missle launchers, printers, external hard drives, 3rd party mouse and keyboard, etc. I have had things act oddly with monitor usb hubs and various combos of usb devices. Try sleeping with no extra stuff hooked up and play try and eliminate.

share|improve this answer
I should have explained clearly, but this is what I meant in #4. Even with no devices plugged in, the machine will sometimes not sleep. I've tried various combinations of hubs, hardware, mice, keyboards, etc, etc. There's no one common piece of hardware that causes it. – EvilChookie Jul 18 '09 at 0:47
Whens the last time you re installed the OS and everything? – Troggy Jul 18 '09 at 8:33
Less than 6 months ago. – EvilChookie Jul 19 '09 at 6:09
Yah, the next thing to check are system logs and see if you can get some direction from any errors. – Troggy Jul 19 '09 at 6:36

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .